The Alarmed Padlock works as a Motion Sensor when it’s locked the 100db alarm will sound when the lock is tampered The alarm will go off giving excellent security to your bikes. fence. gates or any application it is used on Built-in Siren Padlock Dimensions: 3 ¼” x 2 3/16” x 1” 100dB Siren Alarm Zinc alloy 3pcs AG13 button batteries included Comes with 2 keys Country of Origin:- China